A ROSAT Hri Obsrevation of the Cooling Flow Cluster MS0839.9+2938

Abstract

A ROSAT HRI observation of the cluster MS0839.9+2938 at z=0.194 is presented. It confirms the earlier suggestion, based on the detection of extended H$α$ emission, that the inner regions of this cluster are dominated by a cooling flow. The surface brightness distribution within the cooling radius shows structures which can be interpreted as evidence of a highly inhomogeneous space distribution of the cooling process. We note that the brightness at the barycentre of its distribution, which falls right on top of the central giant elliptical galaxy, is lower than the peaks in the structures around: we suggest that this situation is likely to arise as a consequence of photoelectric absorption by cold gas within the cooling flow, with an equivalent column density in the order of 5$\times$10$^{21}$ cm$^{-2}$ within $\sim$10" from the centre.